The invention pertains to the field of surgical instrument systems for supporting eye surgeons in performing eye surgery on the human or an animal eye.
Eye surgeons who perform cataract removal and vitrectomy operations as well as other procedures need surgical instruments which fulfill certain basic needs of the surgeon. The most common of these needs is to cut and remove tissue. Other needs include introducing ultrasonic energy into certain parts of the eye to break up certain undesirable tissue formations, irrigation of the portion of the eye being operated upon, transmitting light into the area of the eye being operated upon, and control of surgical scissors. It is convenient for the surgeon to have an instrument which can perform all these functions under control of the surgeon in the operating room.
Various surgical instruments exist which support various of these functions. However there are few surgical instruments that can perform all these functions. Further, these functions can be done in many different ways, some of which are better than others. For example, it is useful for the surgeon to have vacuum at his disposal to aspirate cut-away tissue and to have complete control of the maximum level of vacuum and the actual level of vacuum in the system under various aspiration conditions. Further, it is useful for the surgeon to be able to request more or less vacuum without having to use his hands or tell another person how much vacuum he wants. If the surgeon accidently aspirates something he or she did not mean to aspirate with the instrument, it is useful to be able to cause a reflux of the system to force the item out of the aspiration line.
Many prior art systems use peristaltic pumps or diaphragm pumps to generate the desired vacuum. These pumps are sometimes noisy and are slow to generate the desired vacuum level. Further, it is desirable to have a fast response time for changes in the desired vacuum levels, and for the system to display both the actual vacuum and the desired maximum vacuum. It is also useful for the system to automatically monitor the actual vacuum level under all aspiration conditions and to automatically adjust it to match the requested vacuum level such that the surgeon does not have to request more vacuum when vacuum in the system falls caused by varying aspiration conditions. Few prior art systems, if any, offer all these features.
It is also desirable for the surgeon to have an instrument which gives him powered surgical scissors which can cut tissue in several modes. A multicut mode where the scissors blades automatically open and close at a frequency controlled by the surgeon is useful. It is also useful to have a mode where the scissors blades close in proportion to the amount of pressure the surgeon places on a foot pedal. Such a scissors mechanisim should be light, small and simple and not pose any danger or electrical shock to the patient or electrical current leakage into the eye in the case of a worn or defective instrument. Few, if any, prior art systems offer all these features.
Further, it is useful for the instrument to be able to support an ultrasonic fragmentation device such that the surgeon can turn such an instrument on and off during the course of a surgery to break up tissue formations ultrasonically.
It is also frequently necessary during posterior work in the eye, i.e., behind the lens, to transmit light into the eye so that the surgeon can see effectively. The prior art instruments sometimes have light probes which carry light from a source in the instrument into the eye. However, the light sources are frequently quite close to the end of the light probe, and, as a result, the light probes get hot enough to burn the fingers of a surgeon or nurse who attempts to remove the probe before it has cooled down.
Few if any prior art systems offer all the useful features mentioned above, and few solve all the problems posed above.